The present invention provides trisubstituted pyrroles as anticoccidial agents, their use in controlling coccidiosis, and compositions containing them.
Coccidiosis is a widespread poultry disease which causes severe pathology in the intestines and ceca of poultry. It is produced by infections with protozoans of the genus Eimeria; some of the most significant of these species are E. tenella, E. acervulina, E. mitis, E. necatrix, E. brunetti, and, E. maxima. This disease is generally spread by the birds picking up the organism at its infectious stage in droppings on contaminated litter or ground, or by way of food or drinking water. The disease is manifested by hemorrhage, accumulation of blood in the ceca, passage of blood in the droppings, weakness and digestive disturbances. The disease often terminates in the death of the animal, but the fowl which survive severe infections have had their market value substantially reduced as a result of the infection. Coccidiosis is, therefore, a disease of great economic importance and extensive work has been done to find new and improved methods for controlling and treating coccidial infections in poultry.
In the poultry industry it is common practice to include anticoccidial agents in poultry feed for most of the bird""s life to control or prevent coccidiosis outbreak. However, there is a risk that the causative organisms will develop resistance after continuous or repeated exposure to any particular drug. Furthermore, conventionally used anticoccidial agents such as sulfanilamides, nitrofurans, quinolines, antithiamines, benzoamides, and polyether-based antibiotics are often toxic to the hosts. Therefore, there is a continuing need to identify new anticoccidial compounds, preferably in a different chemical class from agents currently in use.
U.S. Pat. No. 5,792,778 discloses 2-substituted aryl pyrroles as useful for the treatment of diseases related to excessive cytokine production in mammals. The compound 2-(4-fluorophenyl)-5-(N-methylpiperidin-4-yl)-3-(4-pyridyl)pyrrole is specifically disclosed therein.